1. Field of the Invention
The present invention relates to an electro-optical device, typically an EL (electroluminescence) display device, and an electronic device (electronic equipment) having the electro-optical device as a display.
2. Description of the Related Art
The development of electro-optical devices, typically EL (electroluminescence) display devices using organic material for electroluminescence, has been proceeding at a rapid pace in recent years. There are two types of EL display devices, passive matrix type EL display devices and active matrix type EL display devices.
Regardless of whether a passive matrix type or an active matrix type, the EL display device has a capacitor structure with an EL layer sandwiched by a cathode and an anode (an element having this type of structure is referred to as an EL element throughout this specification), and the EL display device operates under the principle of causing the EL layer to luminesce by the flow of electric current. A metallic electrode is generally used for the cathode, which is an electron supply source, and a transparent conducting film is generally used for the anode, which is a hole supply source. This is done because if one of the pair of electrodes is not transparent, the light emitted from the luminescing layer cannot be extracted.
In this case, the light emitted by the EL layer is directly output to the anode side, and light directed toward the cathode side is also output to the anode side after being reflected by the cathode. In other words, it is necessary for an observer to view the display device from the anode side.
However, light having a wavelength corresponding to the material of the luminescing layer can be seen from a portion of the EL layer emitting light, but in a portion of the EL layer not emitting light, the surface of the back surface side of the electrode (light emitting layer side) can be seen through the anode and the EL layer. This means that the back surface of the electrode therefore functions as a mirror, and the face of the observer is reflected.
In order to avoid this, a method of attaching a circular polarization film to the EL display device so that the observer's face is not reflected is employed, but there is a problem in that the circular polarization film is extremely high cost, therefore leading to increased manufacturing costs.